1. Field of the Invention
This invention relates to an overlapping pedestal secured to a rotating drum, such as a rotating drum of an asphalt cutter and/or a longwall shearer, having a plurality of the overlapping pedestals mounted on the outer drum surface and, more particularly, to pedestals having a first end to overlap with a second end of an adjacent pedestal.
2. Discussion of the Technical Problem
Mining and construction machines having rotating drums are used in underground mining, such as for coal mining, to remove the coal from the mine wall or to remove asphalt from road surfaces. In general, the drum has a cylindrical tubular body having pedestals mounted on the outer surface of the drum to remove the coal or asphalt. In a typical arrangement, a pedestal is welded onto the outer surface of the drum, a block is welded to the pedestal and a tool body with a cutting bit secured therein is secured to the block. The pedestals are oriented relative to one another and to the rotating axis of the drum to have a selected configuration to optimize the removal of the coal from the surface of the mine or the asphalt from the road surface. The orientation of the cutting bits to optimize cutting is well known in the art and no further discussion is deemed necessary.
As is appreciated by those skilled in the art, a machine is taken out of service when its efficiency goes below a predetermined value. The efficiency can decrease for several reasons, one of which is damage to the pedestal, including separation of the pedestal from the drum surfaces. In general, pedestals are secured to the cylindrical drums by welds connecting the base of each pedestal with the outer surface of the cylindrical drum. The pedestals, even though they may be generally adjacent to one another, are not connected to one another. The separation of a pedestal from the drum surface is usually the result of the failure of the weld securing the pedestal to the drum surface. This failure is usually the result of drum vibration and/or shear force acting on the pedestals during operation. Replacing pedestals on the drum surface is a time and labor intensive job. In some instances, the entire drum must be removed from the machine, and the detached pedestals welded onto the drum surface at an off-site location.
As can be appreciated, it would be advantageous to provide a pedestal design that provides improved retention of the pedestals to the drum surface resulting in an improved rotating drum, thereby reducing the down time to replace detached pedestals.